白首乌氮、磷、钾积累分配特点及其与物质生产的关系

Accumulation and distribution of nitrogen,phosphorus,and potassium in Cynanchum bungei Decne and their relationships to dry matter production

在大田条件下研究了白首乌的干物质积累与植株氮、磷、钾积累的特点及其相互关系.对白首乌的干物质积累动态及植株氮、磷、钾含量进行了测定.结果表明,白首乌干物质积累总量随氮、磷、钾积累总量及养分平衡指数（NBI）的增加呈直线增加趋势,相关系数均达显著水平.不同时期白首乌对氮、磷、钾的吸收量不同,在移栽后60 d内对氮、磷、钾的吸收较少,仅占全部吸收量的16.8%、14.4%、15.6%;移栽后60～120d吸收量迅速增加,氮、磷、钾的吸收量占全部吸收量的68.7%、52.3%、58.2%;移栽120 d之后又有所下降.总的来说,植株对钾的吸收量最多,氮次之,磷最少,全生育期内对氮、磷、钾的吸收比例为1：0.8：1.5.

Cynanchum bungei Decne is a Chinese traditional medicine and health food recorded by many ancient codices. It has beneficial effect on blood, liver, and kidney. The planting area of Cynanchum bungei Decne has been gradually increasing these years in China. However, few literatures were recorded concerning the characteristics of dry matter accumulation, and absorption and accumulation of N, P, and K, as well as their relationships of Cynanchum bungei Decne. Therefore, a field experiment was conducted to study the accumulation characteristics of dry matter, nitrogen, phosphorus and potassium of Cynanchum bungei Decne to fill up this blank. The results showed that dry matter accumulation presented a linear increase tendency with the increasing of the total accumulative amount of N, P and K, and nutrient balance index （ NBI）, which reached statistical significance. The absorptive capacity of nitrogen, phosphorus and potassium varied among different developing stages. The absorptive capacity of N, P and K by Cynanchum bungei Decne was comparative lower within first 60 days after transplantation, which only accounted for 16.8%, 14.4%, and 15.6% of the total absorptive capacity, respectively. But it increased rapidly within 60-120 days after transplantation, which accounted for 68.7 %, 52.3 %, and 58.2 % respectively. Thereafter, it decreased. In general, the absorptive capacity of K was the highest, followed by N and P. The N ： P： K ratio was 1 ： 0. 8 ： 1.5 for whole growing stages.